Born in Corinth, Cretheus toured the ancient world in search of knowledge for nine years. When he participated in a competition of intellectuals, he won and earned the Embrace from Mithras, who made him his vizier. He served his sire for the following 600 years, learning the Assamite blood magic known as Dur-An-Ki, while also stayed abreast of Greek philosophy and adapted its ideas to magical use as well. Later, he served as his sire's contact to the Eternal Senate while Mithras took up residence in Londinium and hid Camilla's torpid body at his sire's command.
This vampire was vital for the development of Mithraism, inventing many of the mysteries of the cult and was assigned to supervise the cult during Mithras' periods of torpor. Cretheus, however, failed, as during one of his supervision periods the Roman Emperor Constantine converted to Christianity. Cretheus interest in his sire's cult faded as he begun to research ways to conquer the Beast within and met with Saulot, who told him of Golconda. Nevertheless, he maintained a dislike of Christianity as a pet peeve, supporting actions against the Church.
Cretheus became one of Saulot's most dedicated disciples, forsaking his sire in exchange for salvation. After his master was destroyed by Tremere, Cretheus dedicated himself to preserving the legacy of his teacher, meeting with Mokur and helped to found the Inconnu.
In 1229 CE, he caused the earthquake that reawakened his clanmate Camilla and killed the then current Prince of Rome, Constantius, doing so with the goal of re-enacting the creation of the Baali by making a wellspring of vice from which some would crawl back and might find Golconda.
He was ready to enter the Pact after Mokur's destruction by the hands of Etrius, in exchange for absolute knowledge. Since then, he has tried (without much success) to avoid the intrigues of Hunedoara Castle, dedicating himself on writing down the analects of both Saulot and Mokur to preserve the legacy of the Salubri.
Furthermore, he spends most of his time hunting methuselahs and other agents of the Antediluvians. Cretheus also firmly believes in his own infallibility and power and has dedicated himself fully to the study of Blood Magic to eventually ascend and face God himself. He can only feed from highly intelligent people.